namespace UserAuthApp
{
    class Program
    {
        static void Main()
        {
            // 只负责启动流程，把具体业务交给 UserService 实现
            IUserService service = new UserService();
            service.Run();
        }
    }
}

public class User
{
    
}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 